Underwater Symphony

A symphony is playing in the estuaries of South Carolina—the sounds of shrimp, fish, dolphins, and other creatures. To marine biologists, each sound is like a musical note. Individual notes reveal details about the species that produce them. The symphony reveals the rhythms and health of the complete estuary.

Estuaries are shallow regions where rivers meet the sea. They host a wide variety of life. But the waters tend to be murky, so it’s hard to see what’s going on. So instead, researchers in South Carolina have been listening to estuaries since 2013. They’ve placed a network of underwater microphones on special platforms. They record the soundscape around the clock, along with water and weather conditions.

And there’s plenty to hear: the clicks of snapping shrimp…the purring of weakfish…the grunts of black drum…the calls of bottlenose dolphins…the rat-a-tat of silver perch…

Scientists use the recordings to learn about the habits of all these species—whether they’re more active during the day or at night, for example, or how their activity changes with the seasons. They also learn how each species reacts to hurricanes and other major weather events, as well as human activities, such as boating and underwater construction.

The sounds also help scientists understand whether Earth’s changing climate is jumbling the notes—perhaps throwing the underwater symphony off-key.